Priority Management of Emergency Vehicles at Intersections Using Self-organized Traffic Control

<p>Biologically inspired approaches have the potential to solve many of the difficult networking problems awaiting practical solutions. The recently proposed Virtual Traffic Lights (VTL) is one example (or instance) of this powerful approach for solving some fundamental transportation problems[1], [2]. The successful operation of VTL scheme ultimately depends on the local rules used by vehiclesapproaching an intersection for electing a leader that manages the traffic at that intersection by serving as a virtual traffic light. In this paper, it is shown that by using a different set of local rules atintersections, one can support priority management of emergency vehicles in a self-organized manner. The proposed VTL-Priority Intersection Control (VTL-PIC) protocol can detect the presence of anemergency vehicle and assign priority to the emergency vehicle at an intersection. Large-scale simulation results show that while the travel time of emergency vehicles can be reduced significantly, the impact of the proposed algorithm on the travel time of other vehicles is negligible.</p

Cars as Roadside Units: A Cooperative Solution

<p>The gradual penetration of Dedicated Short Range Communications Radio (DSRC) technology in the years to come is a formidable problem that could adversely affect the implementation of safety and non-safety applications. In this paper, we propose a solution that might mitigate the negative impact of the partial and gradual penetration problem of DSRC technology. The proposed solution is based on a self-organizing network paradigm that draws its inspiration from biological systems, such as social insect colonies [1]. By designing the local rules and a distributed algorithm needed to perform this function, it is shown that DSRC equipped cars can indeed serve as RSUs. Results show that the message reachability and connectivity in urban vehicular networks can be increased substantially in a cost-effective manner as the proposed approach does not entail deployment of infrastructure based RSUs.</p

Increasing Safety and Efficiency of Railway Transport: A Biologically Inspired New Approach

<p>The traffic control systems currently used in rail transportation are heavily infrastructure-based and therefore very costly. This work proposes a biologically inspired solution for the coordination of trains in dense railway networks, avoiding collisions with considerably higher cost efficiency than the state of the art solutions. This solution does not require track mounted infrastructure, instead it relies on the continuous cooperation between trains. Inspired by self-organizing biological systems, two simple algorithms are proposed for managing points of conflict or switches where the right of way or priority of trains has to be carefully handled. The first-level algorithm avoids local collisions by the exchange of status information through beacons. The second-level algorithm uses one-hop or multi-hop communication to share the network status among trains and coordinates the trains in possible conflict zones around switches or in shunting yards. The proposed solution can decrease the signalling cost ofrailway transport substantially. This efficient approach can significantly reduce the probability of accidents caused by human and hardware errors. In addition, the proposed approach can lead to significant time and energy savings in railway transport. The biologically inspired solution proposed in this paper might lead to a paradigm shift in the signalling system used in rail transportation.</p

Using Chinese Remainder Theorem for the Grouping of RFID Tags

<p>In this paper, we propose a novel scheme for the design of grouping of radio-frequency identification (RFID) tags, based on the Chinese remainder theorem (CRT). Grouping allows verifying the integrity of a collection of objects without the requirement for accessing external systems, and can be extended to identify missing objects. Motivated by the redundancy property of the Chinese remainderrepresentation, we propose grouping of RFID tags via the CRT. The proposed scheme not only provides designated decoding guarantees, but also offers flexibility in constructing group generation matrices. We also characterize the key objects needed to study decoding guarantees of grouping and its extended counterpart, called rank-deficient and dead-end sets, respectively, which enable theoretical analyses of error rates. The two key objects are related to the minimum and stopping distances of a linear code, respectively. As such, the characterization offers direct connection with coding theory that helps in the understanding of the verification/identification problems being studied. Theoretical and simulation results are presented, demonstrating that the proposed scheme is an efficient approach to the design of grouping of RFID tags.</p

Robust Design of Two-Dimensional Optical Reference Signals Against Diffraction Effects

<p>This paper presents two novel approaches to the design of two-dimensional (2-D) optical zero reference signals (ZRSs) that are robust against diffraction effects based on the parametric minimum cross-entropy (PMCE) method. Grating alignment systems require a 2-D optical ZRS to perform absolute measurements. A common method of acquiring 2-D optical ZRSs involves illuminating two identical superimposed 2-D zero reference codes (ZRCs). The output signal is the 2-D optical ZRS and can be represented as the autocorrelation of the 2-D ZRC transmittance. In ultrahigh-resolution systems, diffraction distorts the shadow of the first 2-D ZRC, degrading the autocorrelation and greatly reducing the amplitude of the 2-D optical ZRS. To improve the robustness of 2-D optical ZRSs against diffraction effects, this paper formulates two combinatorial optimization problems for the design of 2-D ZRCs with minimum diffraction effects: one of which is a maximization problem, and the other a minimization problem. Aiming at solving the two problems, this study proposes two schemes based on the PMCE method to search for an optimal 2-D ZRC. Simulation results reveal that there are 3.36-8.34% increases in the slope of the central peak of a 2-D optical ZRS and that there are 16.12-20.90% increases in the sum of the slope of the central peak and the effective signal amplitude of a 2-D optical ZRS, as compared with those obtained by the recently proposed cross-entropy method. The proposed PMCE-based schemes prove to search for 2-D ZRCs more effectively than existing solutions, while requiring less computational complexity.</p

A Prototype of Virtual Traffic Lights on Android-based Smartphones

<p>Virtual Traffic Lights (VTL) is a recently proposed self-organizing traffic control scheme that has the potential to mitigate traffic congestion in urban areas. This paper reports a prototype design effort on Virtual Traffic Lights using Android-based smartphones. The experiments performed show the feasibility of implementing VTL using smartphones' WiFi devices.</p

UV-CAST: An Urban Vehicular Broadcast Protocol

Several vehicular communication applications will involve multicast/broadcast communications where all vehicles in a certain region of interest are the intended recipients of particular messages. While there are several existing broadcast routing protocols for highway VANETs, very few solutions exist for urban VANETs in cities like New York City or Chicago. This article attempts to fill this gap by proposing a new broadcast routing protocol, Urban Vehicular BroadCAST (UV-CAST), which addresses both the broadcast storm and disconnected network problems in urban VANETs. Key challenges imposed by urban VANETs as well as new mechanisms needed for meeting these challenges are identified and presented. Performance of the proposed UV-CAST protocol is evaluated in terms of network reachability, received distance, and network overhead in ideal Manhattan Street scenarios as well as in real cities, such as Pittsburgh. The overall performance of UV-CAST is excellent.</p

An Empirical Performance Study of Intra-vehicular Wireless Sensor Networks under WiFi and Bluetooth Interference

<p>Intra-Vehicular Wireless Sensor Network (IVWSN) is a new automotive architecture that applies wireless technologies to the communications between Electrical Control Units (ECUs) and sensors. It can potentially help achieve better fuel economy, reduce wiring complexity, and support additional new applications. In the existing works, most of the popular wireless technologies applied on IVWSNs occupy the same 2.4 GHz ISM frequency bands as WiFi and Bluetooth do. It is therefore essential to evaluate the performance of IVWSNs under interference from WiFi and Bluetooth devices, especially when these devices are inside the vehicle. In this paper, we report the results of a comprehensive experimental study of IVWSNs based on ZigBee and Bluetooth Low Energy under WiFi and Bluetooth interference. The impact of the interference from Bluetooth and WiFi devices can be clearly observed from the experiments. The results of the experiments conducted suggest that Bluetooth Low Energy technology outperforms ZigBee technology in the context of IVWSNs when WiFi interference exists in the car.</p

Improving VANET Protocols via Network Science

<p>Developing routing protocols for Vehicular Ad Hoc Networks (VANETs) is a significant challenge in these large, self-organized and distributed networks. We address this challenge by studying VANETs from a network science perspective to develop solutions that act locally but influence the networkperformance globally. More specifically, we look at snapshots from highway and urban VANETs of different sizes and vehicle densities, and study parameters such as the node degree distribution, the clustering coefficient and the average shortest path length, in order to better understand the networks' structure and compare it to structures commonly found in large real world networks such as small-world and scale-free networks. We then show how to use this information to improve existing VANETprotocols. As an illustrative example, it is shown that, by adding new mechanisms that make use of this information, the overhead of the urban vehicular broadcasting (UV-CAST) protocol can be reduced substantially with no significant performance degradation.</p

Seeing is Believing – Enhancing Message Dissemination in Vehicular Networks Through Visual Cues

One of the stumbling blocks for implementation of Vehicular Ad Hoc Networks is the penetration rate: the percentage of vehicles that have the communication equipment installed. As the equipment deployment is unlikely to happen instantaneously, it is important to explore the performance gains achievable at low penetration rates. This especially pertains to safety applications, which are expected to provide life-saving information to all drivers on the road within a given region. We propose a technique that can be employed by safety applications to address the low penetration issue. By using visual cues on the equipped vehicles, such as specific patterns of hazard warning lights, we show that for all but the lowest vehicle densities, a radio penetration rate of 30% is sufficient to inform more than 95% of drivers in the region of interest in a timely manner.</p